1. Field of the Invention
The present invention is related to a display, and more particularly, to a display including a dielectric layer with a humectant additive.
2. Description of the Prior Art
As flat displays have advantages of small volume and light weight, they are applied in various electrical products. The displaying theory for some flat displays, such as liquid crystal displays (LCD) and electrophoresis display (EPD), includes applying a voltage difference or an electric filed by a top electrode and a bottom electrode to the display medium of the flat display, so as to drive the display medium to display images.
In the flat display, at least one dielectric layer may be located within the displaying electric field that applied by the top and bottom electrodes. Therefore, the dielectric layer will share the applied voltage. In order to achieve the best function of the display, the resistivity of the dielectric layer should be as low as possible, in order to apply enough electric field across the display medium for giving the highest contrast and fastest imaging update speed. However, the electrical properties of the dielectric layers of the flat display are normally various according to the environmental temperatures and moistures, which affect the electrical performance of the flat display. One of the main factors dominating this instability is referring to the moisture level contained within the dielectric layer which is located within the displaying electric field. For example, the moisture level of the dielectric layer would be lower at higher temperature, which causes shifting of the electric resistance of the dielectric layer. And the moisture out of from the dielectric layer would penetrate the electric elements or the display medium, which raise their resistivities. On the other hand, the penetrated moisture may be frozen when the ambient temperature is down to 0° C., which may also induce inappropriate resistance and impact the optical performance as well.
Many conductive fillers, such as conductive nanoparticles, carbon nanotubes, carbon blacks, metal particles an so on, are used to reduce the resistivity for achieving better display performance. However, it is really a challenge to have uniform distribution of the conductive fillers in the polymer matrix. Extra dispersing or process needs to be introduced and the long term stability of the polymer composite fluid is also a concern. Another type of conductive materials that can be used to low down the resistivity is conducting polymer. However, conducting polymers normally need a doping chemical to maintain the polymer at conductive state. However, the compatibility and stability of the doping chemicals bring further complexity to the application. In addition, conducting polymers usually have high cost.
As a result, to provide a display with a stable electrical performance or to maintain the electrical properties of the dielectric layers of the display is still an important issue for the manufactures of displays.